Abstract

Background

The aim of our study was to assess psychiatric symptoms in patients with genetically
proven primary mutation of the mitochondrial DNA.

Methods

19 adults with known mitochondrial mutation (MT) have been assessed with the Stanford
Health Assessment Questionnaire 20-item Disability Index (HAQ-DI), the Symptom Check
List-90-Revised (SCL-90-R), the Beck Depression Inventory-Short Form (BDI-SF), the
Hamilton Depression Rating Scale (HDRS) and the clinical version of the Structured
Clinical Interview for the the DSM-IV (SCID-I and SCID-II) As control, 10 patients
with hereditary sensorimotor neuropathy (HN), harboring the peripheral myelin protein-22
(PMP22) mutation were examined with the same tools.

Results

The two groups did not differ significantly in gender, age or education. Mean HAQ-DI
score was 0.82 in the MT (range: 0-1.625) and 0.71 in the HN group (range: 0-1.625).
Level of disability between the two groups did not differ significantly (p = 0.6076). MT patients scored significantly higher on the BDI-SF and HDRS than HN
patients (12.85 versus 4.40, p = 0.031, and 15.62 vs 7.30, p = 0.043, respectively). The Global Severity Index (GSI) of SCL-90-R also showed significant
difference (1.44 vs 0.46, p = 0.013) as well as the subscales except for somatization. SCID-I interview yielded
a variety of mood disorders in both groups. Eight MT patient (42%) had past, 6 (31%)
had current, 5 (26%) had both past and current psychiatric diagnosis, yielding a lifetime
prevalence of 9/19 (47%) in the MT group. In the HN group, 3 patients had both past
and current diagnosis showing a lifetime prevalence of 3/10 (30%) in this group. SCID-II
detected personality disorder in 8 MT cases (42%), yielding 3 avoidant, 2 obsessive-compulsive
and 3 personality disorder not otherwise specified (NOS) diagnosis. No personality
disorder was identified in the HN group.

Conclusions

Clinicians should be aware of the high prevalence of psychiatric symptoms in patients
with mitochondrial mutation which has both etiologic and therapeutic relevance.